The present invention relates to a backflow preventer which can be placed in a multitude of configurations, and particularly to a backflow preventer with rotatble inlet and outlet fittings.
Check valves are well known for use in assuring that a flow through a conduit occurs only in a predefined direction. Check valves are used, for example, in backflow prevention assembly to prevent backflow of one fluid body into another. Backflow prevention is used in connection with protecting potable water supplies from contaminants which could otherwise be introduced via back siphonage or back pressure. Backflow valves thus are check valves which are designed to accommodate pressures commonly encountered in water supplies, such as about 150 psi or more.
Typically, a check valve is designed to maintain its open configuration as long as there is flow through the valve. Once the flow stops or the line pressure drops below a predetermined value, the check valve closes.
Check valves are typically provided with an inlet opening and an outlet opening, but having only a single predefined configuration of the inlet and outlet openings. Accordingly, when such a backflow preventer is to be installed in a water line, various couplings, fittings, elbows, and the like are used to install the backflow preventer such that the outlet from the water line can be matingly connected to the backflow preventer inlet, and so that the backflow preventer outlet can be matingly connected to the downstream water line. When upstream or downstream stop valves are desired, they are provided as components which must be separately installed. The requirement for such elbows, fittings, valves, and the like creates a number of costs in connection with installation of previous backflow preventers. There is a materials cost in providing such couplings, fittings, etc. There is also a labor cost involved in selecting the appropriate couplings and fittings from the large number which are available, and installing these fittings to mate the backflow preventer with the water line. There is further a maintenance cost, because each coupling which must be added to achieve the desired configuration represents a potential point of leakage.
Typical previous backflow preventers are connected to water lines in an in-line or right-angle position. This connection configuration makes it relatively easy to defeat the backflow preventer using straight line, 90.degree. elbow or spool connectors. Therefore, in previous systems, there was a problem with users removing backflow preventer and replacing them with piping, e.g., to reduce pressure head loss or, during backflow, prevent maintenance or repair, thus endangering the water supply.